A followup to r6828 to fix a condition check in mediasession.cc.

BUG=2395
R=juberti@chromium.org, juberti@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/17029004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6832 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/session/media/mediasession.cc b/talk/session/media/mediasession.cc
index d4ab1f6..7a5d6ac 100644
--- a/talk/session/media/mediasession.cc
+++ b/talk/session/media/mediasession.cc
@@ -1185,8 +1185,8 @@
           return NULL;
         }
         video_added = true;
-      } else if (options.has_data()) {
-        ASSERT(IsMediaContentOfType(&*it, MEDIA_TYPE_DATA));
+      } else if (IsMediaContentOfType(&*it, MEDIA_TYPE_DATA) &&
+                 options.has_data()) {
         if (!AddDataContentForOffer(options, current_description, &data_codecs,
                                     &current_streams, offer.get())) {
           return NULL;